Receptacle closure



July 4' 3Q@ J. B. EISEN ZQSMZ@ RECEPTACLE CLOSURE Filed Nov. 20v 1947 vQa f INVEN'roR Q9 Jay efwafdl'zlsen ATTORNEYS Patented July`4, 1950 garra!)` s'rA'rrssy PATENT ffoFFlcl:

nEoEP'rAoLE oLosURE Jay Bernard Eisen, Yonkers, N. Y., assgnor to Ferdinand Gutmann & Co., Brooklyn, N. Y., a corporation of New York i Application November zo, 1945:, Serin No. 787,133

s claims. (ci. 21a-5s) This invention relates morev particularly to closures for glass or like receptacles that will relieve excess pressure generated in the contained material.

. Where the closure hermetically confines within the receptacle, material that tends to form a gas or vapor under storage conditions, with consequent undue pressure rise, especially on increase of temperature, unless some means is provided whereby such excess pressure may be automatically relieved, the receptacle is apt toA explode with scattering of the glass or other material thereof and spattering of its contents and consequent likelihood of personal injury and property damage.

Where closures are used with venting means therein to permit escape of such excess pressure, it is important that the closures be leakproof under normal pressure and relieve excessive pressure no matter how often the pressure in the receptacle should uctuate. should function only upon the rst undue increase in pressure and remain open thereafter, it would leak and permit escape of the contents of the receptacle; and if the vent should open and then close and thereupon lose its ability to respond to pressure fluctuations, subsequent increases in pressure would cause the receptacle to explode.

Where the pressure relief of such receptacle depends on compression or displacement under excess gas pressure of the relatively thicker compressible paper board commonly used for the cushion liner of the closure cap, there is not suflicient resiliency to afford assurance of adequate` re-sealing after pressure relief, so that a constant slow leak may ensue with loss of valuable more or less volatile or chemically corrosive compurpose, the manufacturing specifications must be highly critical, else the variations inevitable in mass production of the closures will result in a seal that in many cases is either too tight or too loose for its intended'purpose, and these difculties would be aggravated due to the wide manufacturing tolerances in the neck bores of the glass bottles to which such closures are commonly applied.

For if the ventl to the art of packaging,

such low cost, there must be assurance both of adequate closure and of dependable release of pressure in all packages, regardless of the divergenees pointed out, else some or all of the difiiculties above referred to may arise.

It is accordingly among the objects of the invention to provide a closure for a receptacle that tightly seals the `mouth against leakage under normal pressure conditions, yet is effective to release excessive pressure generated by the contents of the receptacle and reliably to reseal after such release and so functions with uniform dependability, no'matter how often and at what intervals excessive pressure should develop, that has but few inexpensive parts which may be pro,

duced without close manufacturing tolerance, by standard bottlecap making machinery and the reliability of which is not affected by the usual divergence in the neck bore diameter of receptacles to which the closures are applied'.

According to the invention, the' closure need departvbut slightly from the physical structure of the usual screw-on bottle cap with its thicker cushion liner of paper pulp and its thinner impervious facing liner, in order to permit a portion of the facing liner to act as a safety valve and to move relative to the cushion liner away from the receptacle rim for pressure relief.

To this end, a recess is provided in the periphery of the cushion' liner so that with the facing liner against the latter, that portion of the facing liner straddled bythe recess will be spanned thereacross as a relatively taut membrane valve.

excess pressure evolved Within the package Will l cause only the span of the membrane valve portion of such facing liner to become tensed, and this without rupture by virtue of its appreciable elasticity and todegree Vwell within its elastic limit. Accordingly, said membrane valve will As the closures are utilized for receptacles that bow slightly away from the receptacle rim into the recess in the cushion liner to break the seal and thus permit escape of gas or vapor from the package for pressure relief. By virtue of its appreciable elasticity, the tense and bowed span of the membrane valve after relief of excess pressure, automatically contracts to return to fiat seating position against the receptacle rim, thus to re-seal the receptacle.

The present application is a continuation in part of my prior application Serial No. 595,690, filed May 25, i945, now abandoned.

In the accompanying drawings in which are shown one or more of various possible embodiments of the several features of' the invention,

Fig. l is a perspective view of the closure applied to the neck of a glass receptacle,

Fig. 2 is a sectionalview of the closure taken along line 2-2 of Fig. 1.

Fig. 3 is a view similar to Fig. 2 with the parts in venting position,

Fig. 4 is a perspective view of the closure in venting position, with parts broken away.

Fig. 5 is a perspective view of the cushion liner showing the notch therein,

Fig. 6 is a view similar to Fig. 5 of the facing liner, 1

Fig. 7 is a fragmentary sectional view of the facing liner taken along line 'l-l of Fig. 6 showing the coating thereon, greatly magnied in thickness, and

Fig. 8 is a perspective view with parts broken away of another embodiment of the cushion liner with a facing liner in juxtaposition thereto, and partly broken away.

Referring now to the drawings, the closure, which preferably is oi the screw-on type, comprises a cap ii having a head I2 with a depending skirt or ange I3 formed integrally therewith, the latter having a screw thread I4 for engagement with the correspondingly threaded neck i5 of a receptacle I6 which latter is illustratively a glass bottle, as shown, but which could be of metal or plastic. It is to be noted, however, that the invention herein is applicable to closures having other forms of receptacle engagement such as coacting lugs or a beading on the receptacle over which theange or skirt of the closure is crimped, the latter type of closure being commonly known as a crown cap. The lower edge of the skirt I3 is,rolled outwardly to form a strengthening beading I1 while the upper part of the skirt i3 adjacent the head I2 is knurled as at I8 to strengthen the cap and give rigidity.

thereto and also to facilitate application to and removal of the closure from` the neck of the bottle.

Seated within the closure against the under face of the head I2 thereof and having substantially the same diameter, is a disc-shaped cushion liner 2| preferably of material such as pulp board which is slightly compressible so as to lend itself to the formation of a tight seal when the closure is applied to the neck of the bottle and which is sufficiently resistant so as not to become materially deformed when pressure is applied thereto. Formed in the periphery of the cushion liner 2l and preferably extending through the thickness thereof is a recess 22 which preferably has the shape of a triangle, with a rounded apex 23 and a flared base 24. The particular conformation of the apex and base of the recs herein shown makes for more emcient operation, for with a sharp apex and base, there is a tendency for fibers of the pulp board to cling and accumulate, causthe release of the excess pressure. Although the V-shaped recess has been shown as a preferred embodiment as tests have shown this form to be most effective, the recess could be of other suitable shapes such as a U-shape. Y

A disc shaped facing liner 25 is also prOvided, of

substantially the same diameter as the cushion.

liner 2l but oi much less thickness and of material that is both flexible and appreciably elastic and is also resistant to chemical or other reaction by the contents of the receptacle. The facing liner which, unlike the cushion liner 2i, is anI uninterrupted disk, is seated against the outer face 26 of the cushion liner and spans, preferably wholly covering the recess 22 therein, so that under normal pressure there is no direct communication between the recess and the interior of the bottle, and the facing may be secured, if desired, to such cushion liner by the application of a suitable adhesive at the center thereof as at 21.

Inasrnuch as in mass production of the glass bottles to which the caps of the present invention are commonly applied, the neck dimensions vary considerably and the apex of the recess 22 must always extend somewhat inwardly of the bot.- tle rim in order for the excess. pressure to deect the membrane valve, it is merely necessary for the radius from the center to the inner end of the recess to be somewhat less than the minimum bore radius of the lot of bottles. The safety valve will function equally well with a bottle bore radius greater than the minimum, the membrane valve 25', in that case opening under somewhat lower pressure than in the case of a bottle of minimum bore radius.

In the embodiment herein in which one particular type of facing liner is shown to illustrate my invention, it preferably comprises a disc 28 of sulilte paper approximately .004 inch thick, coated on its lower face as at 29 with a synthetic resin such asVinylite that comprises a copolymer of vinyl chloride and vinyl acetate and has a thickness of approximately .0008 inch. The physical characteristics of the copolymer are such as to contribute flexibility and elasticity to the liner. Thus when that portion of the facing liner straddled by the recess, is bowed therein under application of pressure thereto, as will be hereinafter described, it will restore itself to its original condition when the pressureV is relieved.

In a typical package with e. cap having an outside diameter of approximately 1511s inch, the recessed cushion liner should have a diameter of approximately .915 inch and be approximately .Q40 inch thick, the triangular recess thereof having a base approximately .125 inch wide and a radial depth of approximately .125 inch, resulting in an angle at the apex of approximately 53 degrees, the apex being preferably rounded and the base flared, as heretofore described. A cap of the specifications mentioned will thus be applicable to any lot of bottles whose neck bore radius at the rim or sealing surface of the bottle is larger than .350 inches and is anywhere between the limits of the relatively wide tolerances of bottle necks fitted by caps of the dimentions set forth. With any bottle of such dimensions, the recess 22 will extend inward suiciently beyond the seating rim to function in the manner set forth.

When the closure is affixed to the neck of the bottle in conventional manner, either by the conventional cap machine or manually, the facing ing an irregular recess which might interfere with u liner 25 becomes seated at its periphery against the rim 3| of the bottle, establishing sealing contact therewith under the pressure thereby ex erted by the head I2 of the cap il through the cushion liner 2l. The cushion liner is sufficiently resistant to avoid any substantial deformation of l the recess 22 therein under such pressure, so that the latter remains open at all times. That portion of the facing liner straddled bythe recess of said seal is e'ective to withstand pressure,

well in excess of that due to the pressure head thereagainst of the package contents upon inverting the bottle. Upon evolution of excess gas or vapor pressure within the bottle, only the membrane valve can and will yield, since the main periphery of the facing liner is securely clamped against the bottle rim. The membrane valve thus becomes tensed under such pressure to bow away from the bottle rim into the recess 22 for relief of pressure by escape of gas or vapor. sion of the span of the membrane valve is precluded, the elongation thereof remaining well within its elastic limit, and there is no danger of tearing the relatively thin membrane 25' in the safety valve action.

After excess pressure has been relieved, the tensed span of membrane valve will contract to return to its original at condition into sealing engagement with the bottle neck in readiness at all times to act as often as required as a safety valve for relief of excess pressure.

Thus the only structural change made in the conventional bottle cap to incorporate therein the safety valve feature of the present invention, is to notch the cushion liner as at 22. This may readily be done by a slight alteration in the stamping die for the cushion liner, to include the recess forming conformation therein. Accordingly, the material used for the closure,`and (except for such modification of one stamping die) the machinery for manufacturing the same are identical with those from which a conven-A tional bottle cap is made. Accordingly, manufacture of the safety valve equipped cap involves no complication or addition inl cost as compared with the manufacture of the conventional bottle cap devoid of the safety feature.

The adhesive connection 2'! between the cushion liner 2i and the facing liner 25 may be dispensed with, but is desirable to prevent the facing liner 25 from falling out of the closure when the latter is removed for dispensing. The area of adhesion 2l should be relatively small and remote from the recess 22 in the cushion liner as the engagement of the membrane valve 25 with adhesive, as for instance by applying adhesive to the entire area of the facing liner may seriously impair the functioning of the membrane valve.

For bottles of larger neck diameter containing viscous materials, such as marshmallow paste, the correspondingly large cap, illustratively having approximately a 2.5 inch outer diameter may have a cushion liner of 2.410 inches in diameter and .03 inch thick, preferably with a plurality, desirably three evenly spaced recesses 22 in the periphery thereof, as shown in Fig. 8. Each recess 22' is shown in the shape of a, triangle with a rounded apex23 and a ared By such pressure relief, excessive tenwide with a radial depth of approximately .484 v inch, resulting in an angle of approximately 24 degrees at the apex.

Because there is less likelihood. of Vleakage of the more viscous contents and hence greater danger of the building up of excess pressure in the bottle to shatter the same, the greaterpnumberof larger safety valves are provided. A less expensive material such as parailln, may be used to coat the facing liner of the closure for the y bottle because the viscous material therein does not easily leak and hence a closure facing material with lower elasticity thatA may engage the bottle rimvless intimately may Ibe used for the p seal.' v

As many changes could be made in the above y construction, and many apparently widely dif ferent embodiments of this invention could be made without departing from the scope of the claims, it is intended that all matter contained in the above description or shown in they accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is: y

1. A closure for receptacles the contents of which are subject to the evolution ofv pressure during storage, said closure being of the type comprising` a, cap having a relatively thicker cushion liner of slightly compressible material and a relatively thinner flexible facing liner substantially impervious to the receptacle contents, having appreciable elasticity and normally having its periphery in engagement with the rim of such receptacle; the combination in which said cushion liner has a recess in its periphery through the entire thickness thereof of radial depth to extend inwardly slightly beyond the facing-liner-engaged rim of such receptacle, and said facing liner is uninterrupted at and presents a portion spanning said recess, whereby upon evolution of excessive pressure within such receptacle, the portion of the facing liner spanning the recess in the cushion liner will be deflected olf the rim of such receptacle into said recess for relief of excessive pressure, the portion of said facing liner deflected into said recess, returning by virtue of its appreciable elasticity against the rim of such receptacle to re-seal the latter upon relief of such excessive pressure.

2. In a receptacle closure of the screw-0n type that comprises a head having a skirt depending therefrom to encompass the neck of a receptacle when aillxed thereto, a, relatively thicker pulp board cushion liner substantially uniform in thickness and a relatively thinner facing liner having appreciable elasticity and positioned in said closure, said cushion liner being positioned adjacent the underside of said head and said facing liner being positioned adjacent the undersurface of said cushion liner, said facing liner having a seating periphery to engage the rim of such receptacle to seal the latter; the combination wherein said cushion liner has a recess therein extending inwardly from its periphery through the entire thickness thereof and of radial length to extend inwardly of said rim, and said facing liner is uninterrupted at and presents a portion spanning as a membrane over said recess and tensing and bowing into said recess under excessive pressure within such receptacle, whereby the seal is broken at that point to relieve such excessive pressure within such receptacle, said base 24', the base being approximately .25 inch 7| membrane by virtue of its appreciable elasticity resuming its normal sealing position upon relief of such excessive pressure.

3. A closure for receptacles the contents of which are subject to the evolution of pressure during storage, said closure being of the type comprising a cap having a relatively thicker cushion liner of slightly compressible material and of substantially uniform thickness and a relatively thinner, flexible, appreciably elastic facing liner` of paper stock o! substantially uniform thickness in the order of .004 inch, in engagement on one face with said cushion liner and having an appreciabiy elastic coating on its other face substantially impervious to the receptacle contents and having a seating periphery to engage the rim of a receptacle to seal the latter;

' the combination in which said cushion liner has a V-shaped recess extending therethrough inward from its periphery to slightly beyond the closure seating rim of such receptacle, and said facing liner is uninterrupted at and presents a portion spanning said recess, said liners being adhesively connected together at a region spaced from said recess, whereby that portion of the facing liner which spans the recess constitutes a v-shaped membrane to be tensed and bowed into the recess by increased pressure within said receptacle v,to unseal the latter and to be self restoring to sealed position upon relief of such increased pressure.

4. A closure for bottles, the contents of which are subject to the evolution of pressure, said closure comprising a screw-on type cap having a relatively thicker paper pulp cushion liner therein and a relatively thinner, appreciably elastic facing liner of sulte paper having its inner face in engagement with said cushion liner and having a coating on its outer face comprising a copolymer of vinyllchloride and vinyl acetate, said coated face having a seating periphery to engage the rim of such bottle, said cushion liner having a recess in its periphery 8 through the entire thickness thereof'of radial depth to extend inwardbeyond the closure seating rim of such bottle, said facing liner being uninterrupted at and presenting a portion span.

ning said recess. whereby upon evolution of excessive pressure within such bottle, woll above the pressure head created by the contents of the inverted bottle and well below the bursting point of the bottle, the portion of the facing liner which spans the recess is tensed and deflected ofi the bottle rim into said recess as a membrane valve. said membrane valve by virtue of its appreciable elasticity returning against the rim to re-seal such bottle upon relief of such excessive pressure.

5. The combination recited in claim 1, in. which the cushion liner is of pulp board and the facing liner is coated with paraiiln wax.

6. The combination recited in claim l, in which the cushion liner has a plurality of the recesses set forth spaced along the peripheryA thereof and in which the facing liner is coated with paraiiln wax.

JAY BERNARD EISEN.

REFERENCES CTED The following references are of record in the le of this patent:

France Feb. 28, 1941 

